The long-term goal of the research endeavor focuses on a theoretical account of bimodal speech perception, or speech perception by eye and ear. The research is carried out within the framework of the falsification and strong-inference paradigm to eliminate alternative interpretations and to provide constraints on proposed theoretical explanations. The experiments utilize the methodology of information processing, information integration, and the testing of mathematical models. A wide variety of experimental tasks perceptual judgments, and dependent variables are studied to provide converging operations on the phenomena of interest. The proposed research is aimed at understanding the evaluation and integration of auditory and visual information in speech perception. The experimental studies address 1) the ability to learn to attend selectively to one modality or the other in bimodal speech perception, 2) the degree to which preschool and adolescent children can be taught lipreading and the consequences of learning on bimodal speech perception, and 3) the psychophysical study of audible and visiblespeech involving the extension of forms of degradation of the auditory speech and the assessment of various forms of degradation of the auditory and visual signals.